1. Field
The invention relates to a display device and an optical film included in the display device.
2. Description of the Prior Art
With the development of multimedia, the importance of display devices has increased. To cope with this, various kinds of display devices, such as a liquid crystal display (“LCD”) and an organic light emitting display (“OLED”), have been used.
Among them, the LCD may include thin film transistors, pixel electrodes, common electrodes, and liquid crystals interposed between two substrates that face each other. Operation modes of a liquid crystal layer may include a twisted nematic mode and an electrically controlled birefringence mode. The electrically controlled birefringence mode may include a vertical alignment mode, an optically compensated birefringence (“OCB”) mode, and an in-plane switching (“IPS”) mode. According to an example of a driving method of an LCD, when an electric field is formed between the pixel electrode and the common electrode, liquid crystals in the liquid crystal layer may be arranged at an angle that is smaller than 90° with respect to the pixel electrode or the common electrode to implement an image that is gradually brightening.
Recently, research has been conducted for expanding a viewing angle on the side in addition to a viewing angle in front of the LCD.